The central hypothesis of this proposal is that a disease management (DM) program will improve the quality of care to adults with asthma in Medicaid HMOs. To test this hypothesis, a randomized controlled trial will evaluate the clinical effectiveness and economic impact of a DM program in ambulatory practices. The main clinical indicators will be numbers of emergency department (ED) visits, hospitalizations, restricted activity-days, symptom-free days, and use of oral steroids. The main economic indicators will be the total, average, and incremental costs as measured by programmatic and health care costs in the first year of the program. We will also calculate standard economic ratios such as incremental cost per incremental outcome. The main outcomes in this study will be the DM program's effect on restricted activity-days, symptom-free days, health status, and quality of life. The specific aims of this study are to: 1) use a randomized controlled clinical trial of primary care practices to assess the effect on clinical outcomes of a DM program for adults with asthma; 2) assess the effects of the DM program on patient-reported health status and quality of life; 3) explore the effects of the DM program on medical service utilization, including prescription drug use; and 4) conduct a programmatic and per patient economic analysis of the DM program. The results of this study will increase our understanding of how a DM program, based in primary care practices, can affect clinical outcomes, health status, and costs in adult asthma. This study will provide relevant and timely information for health care organization, planning, and delivery by alerting decision makers to effective program development and use of resources. It will extend findings of other DM studies by: (i) using a rigorous controlled trial methodology to assess programmatic and economic results; (ii) applying the intervention to patients at high risk because of their clinical severity and SES status, and (iii) evaluating outcomes in terms of both health care utilization and health-related outcomes.